1. Field of the Invention
The present invention relates to a device for insertion and assembly of workpieces and the method thereof used when effecting the assembly of a workpiece to a workpiece in assembly lines for drive units, various types of precision machinery, automobiles, etc.
2. Description of the Related Art
Before now, the device disclosed in Japanese Patent No. 8-215947 was known as a device for assembling a torque converter in a transmission, in the assembly of automatic transmissions for automobiles, for example. This device prevents the co-rotation of the axial shaft of the torque converter and the spline axis of the transmission and effects the fitting together of the workpieces in a short period of time. For this reason, it is equipped with the following: means for driving tables fore and aft to support tables which move fore and aft, such as a mobile plate and an insertion plate, approachably and retreatably with respect to one workpiece, and to move these tables which move fore and aft, means for holding a workpiece to hold the other workpiece installed on these mobile tables, means for rotating workpiece to rotate either workpiece when fitting said pair of workpieces, and means as a pusher cylinder for advancing and retreating workpieces for fine movement of one workpiece in a direction away from the other workpiece when fitting said pair of workpieces.
In the conventional device, automatic assembly is effected as a drive cylinder 51 moves mobile and insertion plates 47 and 48 close together in the direction of the torque converter and drives a rotary unit 102 arranged so as to straddle the insertion and mobile plates, the torque converter is rotated and centered, the insertion cylinder 54 installed on the side toward the mobile plate is driven and the insertion plate 48 is moved with respect to the mobile plate, and the position of the insertion plate 48 approaching the torque converter is detected, meanwhile the pusher cylinder 57 is moved fore and aft and the action of finding the fitting position is effected. However, this device requires the drive cylinder 51, insertion cylinder 54, and pusher cylinder 57 for just advancing and retreating movement of one workpiece with respect to another workpiece; control becomes complex which affects costs and results in decreased precision due to a plurality of cylinder mechanisms. Moreover, the device becomes large and heavy and manufacturing costs are high because these cylinder mechanisms are in a state of being mounted on a plurality of tables and driving is effected for each table. Another disadvantage is the problem of precision. Furthermore, with this conventional device, the minimum number of cylinders is three due to the use of driving cylinders all using air pressure in order for the advancing and retreating movement. Otherwise, solenoid valves for driving cylinders, regulators for air pressure control, and solenoid valves to control that, etc., become necessary, the number of parts used for driving becomes high, and control becomes complex. Meanwhile, problems with the conventional device include: control of position and control of pressure both become--necessary because it is the amount of advancing and retreating movement of the cylinders which produces the fitting, or not, of one workpiece to another; and in practice, it is difficult to effect the fitting of spline and engagement axis so smoothly because it is determined whether both workpieces are in contact or not through detecting the position with sensors and either workpiece is rotated when in a state of contact under the fixed pressing force from the cylinders. Furthermore, another problem is that the workpiece of setting the conditions is very difficult and lacking in flexibility because, when effecting various settings in the assembly workpiece with the conventional device, insertion speed and rotation speed are different depending on the type and model of workpiece and the control of two systems, the control of pressure, and the control of position, must be effected at the same time.